Loading attachment fob tractors



'G. e. M NAMARA, JR

LOADING ATTACHMENT FOR TRACTORS 4 Sheets-Sheet 1 Filed Dec. 27, 1946 Q'JI Q y 15, 1952 G. G. M NAMARA, JR 2,603,374

LOADING ATTACHMENT FOR TRACTORS Filed Dec. 27, 1946 4 Sheets-Sheet 2 y 1952 G. G. MONAMARA, JR 2,603,374

LOADING ATTACHMENT FOR TRACTORS Filed Dec. 2'7, 1946 4 Sheets Sheet 5 JJd 6 G7 I ca, 65 75 7a o 75 0 1a 91 1 I Gamble G/l/Wd E y 1952 G. G. MGNAMARAJ'JR 2,603,374

LOADING ATTACHMENT FOR TRACTORS Filed Dec. 27, 1946 4 Sheets-Sheet 4' Patented July 15, 1952 LOADING ATTACHMENT FOR TBAGTORS Gordon G. McNamara, Jr., Chicago, Ill., assignor to International Harvester Company, a corporation of New Jersey Application December 27, 1946, Serial No. 718,675

11 Claims. 1

This invention relates to a load moving machine, and more specifically to a tractor-mounted loader. v

The invention pertains especially to improvements in the structure of machines known as power loaders. A typical loader consists of a loader attachment which is readily adapted to be attached to a tractor. The structure generally comprises a rigid frame having a pair of laterally spaced arms pivotally connected to the frame for vertical movement. A material handling means, such as a scoop, is pivotally connected to the arms for movement therewith from the ground to a lifted position. The tractor furnishes the power for lifting the scoop and its supporting structure. Loaders of this type are especially adaptable for use on farms where they are utilized for 'a various number of chores, such as manure handling, grain handling, etc.

In the handling of manure and other materials, the loader is forced into the mass of material by the traction of the tractor. The greatest stress on the loader and the tractor is generally found during the beginning of the lifting operation. At this point the stress is great since the material which has filled the scoop must first be broken free of its mass. This condition is especially found prevalent during the winter months when the material or manure is generally in a frozen condition and is very tightly packed. This initial lifting force then exerts an unsual amount of pressure on the body of the tractor which therefore must be built to withstand these unusual loads.

It is the principal object of this invention to provide an improved loader attachment for a tractor, said attachment including a material moving scoop which is adapted to be supported on the ground during the initial loading and ground breaking operation thereby carrying and absorbing the heaviest stresses independently'of the tractor.

Another object is to provide an improved scoop for a loader attachment, said scoop having a material engaging edge which may be raised vertically with respect to the heel of the scoop which is resting upon and is pivotally supported on the ground.

Another object is to provide an extensible power means and linkage therefor for tilting the scoop portion of a loader attachment, said tilting movement being effective to break loose the material from its mass during the initial operation of the scoop.

still another object is to provide a power 2' loader having extensible power means for tilting the material handling scoop whilesaid scoop is resting on the ground, said extensible power means also being operable to raise the scoop to a loading position.

loader in a tilted position, said tilted position being initially assumed during the engagement of the scoop with the material to be handled. H

Another object is to provide a fluid control means for dumping the material handling scoop, said control means also being eilective .topermit angular adjustment of said scoop.

Other objects will become more readily apparent as the description proceeds when read in conjunction with the accompanying drawings in which:

Fig. 1' is a side elevational view of a tractor having a power loader connected thereto;

Fig. 2 is a plan view of the same;

Fig. 3 is a side elevational diagrammatic view showing the first stage of the operation of a tractor-mounted power loader;

Fig. 4 is a diagrammatic side elevational View showing the tractor-mounted power loader'in its extreme lifted position;

Fig. 5 is a diagrammatic elevational view of-a tractor-mounted power loader showing'the same in a dumped position;-

Fig. 6 is'a detail sectional view taken along the line 6-6 of Fig. 2;

Fig. 7 is a detail plan view of a fluid pressur means for locking a tractor-mounted loader scoop' in atilted position; and v1 Fig. 8 is a sectional View taken along the line 8-8 of Fig.7. a Referring particularly to Figs. 1 and 2,-a tractoris generally designated by the reference character l0. The tractor It includes a longitudinal body portion II mounted on front rolling suptransversely extending angle bar '2l and plate members 22 which are suitably fastened to the body of the tractor by means of bolts 23. Positioned at each side of the tractor and rigidly connected to the longitudinal members l8 are a pair of upwardly converging member 24. The upper portions of the converging members 24 are connected by means of vertical angle members 25. The angle members 25 have connected thereto bearing plates "26 through which a transverse shaft 21 extends for pivotal movement. A bracket 28 is rigidly secured to th rear portion of the vertical angle members, 25 and .has connected thereto a transverse beam member 29.

A loader frame is generally indicated by the reference character 30 and includes forwardly and downwardly extending frame members 3! which are pivotally connected .tothe brackets '28 as indicated at 32. Connected to the forward portion of each side frame member 3| is a verticalqplate 33. Transvers torque members 34 are rigidly secured-toeachplate 33 thereby forming a rigid frame structure. A-pair of laterally spaced upright or vertical arms 35 are-positioned at the foremost portion ofthe laterally spaced vertical plates 33. The arms 35 are normally in vertical or upright position during the lowered position of the loader. The terms upright or "vertical are. therefore, merely used in an identifying manner rather than in a restrictive sense since, as shown in Figures 4 and i5, the arms 35 are no longertruly upright vor "vertical when the loader is in its maximum raised .position. Each upright arm .35 is pivotally connected intermediate its ends about atransverse vaxis to the plates .33 ;as indicated by the referencecharacter .35. The'upright arms 35 are oscillated about the connection 36 by means of laterally spaced crank arms 31. The crank arms 31 are pivotally-connected to laterallyspaced longitudinal links 38 whichtare in turn'pivotally connected to the upright arms 35 by means of alaterally extending shaft 39. The crank arms 31 are rigidly secured to a transverse shaft 31' which is Journaled in bearing portions 38' rigidly carried by the vertical plates.

A load carrying means or scoop 40 is pivotally connected .to and between the upright arms 35. The :scoop 43 includes sideportions 4|, a closed end or heel portion 42 and aiload engaging edge 43. As'best shown in Fig. l'the pivotal point .of connection 4|, between the scoop 40 and the upright arms. 35, is forwardlyof the heel of the scoop and some distance above .theground. The position of this connection provides fora pivotal tilting of the scoop about its'heel as will presently become more apparent.

Power for tilting and raising the loader scoop is provided by 'means of laterally spaced xtensible power means 44. Each extensible power means 44 includes a fluid cylinder 44' which is pivotally connected to each of the vertical angle members 25. Apiston 45 is mounted for reciprocation within each cylinder 44 and has connected thereto a piston -rod45. The piston rod 45 is connected at its forward end to a crank member '41 which is best shown in the broken away portion of the construction as shown in Fig. 2.

Referring particularlyto Figs. 2 and 6, a pair of triangular laterally spaced plate members 48 are'rigidly secured to the foremost torque member-34. 'lhetriangular plate members 48 include a. pairgof bearing sleeves 49 "through which the transverse shaft 31' extends and on which it is journaled. Substantially centrally positioned between the bearing sleeves 49 are a pair of depending arms 50 which are rigidly secured for rotational movement with the transverse shaft 31'. As indicated at 5| and 52 in Fig. 6, a fluid pressure means or check cylinder 53 is connected to and between the depending arms 50 and the triangular plates 48. As best shown in" Figs. 7 and 8, the fluid pressure means 53 includes a cylinder 54. A piston 55 is mounted within the cylinder 54 for reciprocation and has connected thereto a piston rod 56. A bolt 51 secures the end of the piston rod 55 to the depending arms 50. A bolt 57' firmly anchors the end of the cylinder 54 between the triangular plate members 4B.

As best shown inFig. 8, the fluid pressure means 53 includes a valve construction generally indicated by the reference character 58. The valve construction 58 further includes a valve housing 159 provided with areservoir chamber .60. The valve construction 58 is preferably mad of cast iron construction and includes a bored opening 6|. The bored opening 6| is threaded at each of its ends and has screwed therein a threaded valve body 52. The threaded valve body'62 is provided with a bored chamber 63 which has an internally threaded portion 64. A threaded plug 55 is screwed into the threaded portion of the threaded valve body 52. Slidably positioned withinthe bored chamber 53 is a sliding thrust member 55 having openings 51 which placerone end of' the chamber 63 in communication with its other end. The sliding thrust member 66 is continuouslyforced in one direction by means of a spring 68. A conduit 59 provides for communication of the chamber 53 with aconduit 10. The threaded plug 55 is formed with a valve seat 1| which supports the ball valve 12. The ball valve 12 is compressed against the valve seat TI and shuts off a bored chamber 13 formed in the threaded plug 55. The chamber 13 is in communication with inlets 14 which in turn are in communication with openings 15 of the valve body 62. The openings 15 are in communication with a conduit 15'. The conduit 15 is in communication with one end of the cylinder 54 and the conduit 18 is in communication with the other end of the cylinder 54. The threaded plug 55 has a bore or guideway 15 in which a plunger 17 reciprocates.

The plunger :1 forms part of a piston structure 18 which is reciprocable within the bored opening 6|. A packing disk 19 is placed in back of the piston structure 18 for suitably sealing the bored opening 6|. A projecting circular portion is integral with the piston structure 18 and is in abutment with a threaded cap 8| which is screwed into the end of the bored openings. The cap 8! is provided with an opening 82 in which a conduit 83 is connected. An opening 84 provides for communication with the bore ti and the reservoir 60.

As best shown in Figure 1, an extensible fluid pressure means is generally indicated by a reference character 85. The pressure means 85 includes a cylinder 86 which is pivotally connected to one of the vertical angle members 25 and extends upwardly with respect thereto. The cylinder 86 has a piston 81 reciprocally mounted therein. The piston 81 is connected to a piston rod 88 Which in turn is connected at its end between the crank elements 89. As best shown in Fig. 2, the crank elements 89 are rigidly connected to the transverse shaft 21 and are adapted to rotate with said shaft. A pair of upwardly extending arms 90 are each secured tothe ends of the transverse shaft 21 and each have connected thereto a downwardly extending link 9|. The links 9I are each connected toa jack-knife link construction generally referred to by the reference character 92. As best shown in Figs. 1,

2, and 3, the jack-knife link construction 92 includes an upper link 93 and a lower link 94. The upper and lower links 93 and 94 are pivotally connected together as indicated at 95. As shown in Fig. 5 and indicated by the reference character 96, each lower link is pivotally connected to the rear portion of the scoop 40. As best shown in Fig. 4, each upper link 93 is pivotally connected to each link 9| as indicated at 91.

The fluid pressure means for controlling the action of the extensible means 44 and 85 includes a control rod 98 which is readily operable from the operators station I5. The control rod 98 is associated with a fluid reservoir and pump (not shown) which is mounted within the longitudinal body II of the tractor. The reservoir and pump is of conventional design and need not be further described for the purpose of this invention. A conduit 99 is in communication with the fluid reservoir at one end and is connected at its other end to a fluid control box I00. The fluid control box I!) is mounted in proximity to the operators station I and is at all times within manual control of the operator. The manual control box IGIJ includes control levers IIlI, I02, and I03. The control lever IIl-I may be actuated for regulating fluid to a conduit I04 which is in communication with the foremost portion of the cylinder 44'. Fluid through a conduit I05 may also be regulated by the control lever IN, the conduit I95 being in communication with the other end of the cylinder 44'. The control lever I02 may be actuated to supply fluid to a conduit- I06 which is in communication with the cylinder 85. The control lever I 03 may be actuated to supply fluid to a flexible conduit I07 which is in communication by means of pipe joints I58 with the conduit 83 leading to the valve construction 58. Cross feed conduits I09 and III] are respectively in communication with conduits I04 and I05 for supplying fluid to the cylinder 44 on the opposite side of the tractor. For the purpose of clarity, in Figures 2, 3, 4, and 5, the conduits have been broken 01f or omitted. I

During the cycle of its operation, the material handling scoop 4B is resting upon the ground as shown in Figure 1. Forward movement of the tractor shoves the scoop 48 into the mass of material to be handled. Since this mass of material may under various conditions be very compact, frozen, or otherwise difficult to break loose, it is therefore first desired to tilt the scoop, thereby loosening the material so that the loaded scoop may be readily lifted.

The operator initially actuates lever IBI by rocking the same in one direction, whereupon.

fluid flows through the conduit Illfil into the cylinder 44. The fluid pressure thereupon actuates the piston 45 to move rearwardly. As the piston 45 moves rearwardly, the piston rod 46 rocks the shaft 31 in a clockwise direction. As the shaft 31' is rocked in the clockwise direction, the crank arm 31 forces the links 38 rearwardly thereby causing pivotal movement of the upright arms 35 about their transverse axis 35. By virtue of the counterclockwise oscillation of the arms 35 movement of the scoop 40 is effected. Byvirtue of the jack-knife linkage arrangement 92,

which is pivotallyconnecte'd. to the links Ill, and in view of the oscillating movement of the arms 35, the material engaging edge of the scoop 40 islifted vertically and the scoop is rotated with the heel; thereof being supported on the ground. The jack-knife linkage causes the upward tilting of the scoop in a rapid manner without substantial oscillatory movement of the arms 35. exact action of the jack-knife linkage and the movement of the scoop 40 is as follows: As the arms 35 are pivoted with their upper ends moving rearwardly, the lower ends of the arms 35 are moved forwardly a short distance, thus moving the scoop forwardly. Simultaneously the upper ends of the links '93 are moved rearwardly a'nd' during this movement they pivot on the links 9I also causing the links 9I topivot on the arms 96. The arms 90 are at this point stationary since the jack 85 is not in operation. The pivoted points of connection of the links SI to the links 93 also move downwardlyand rearwardly. As the ends of the links 9| are moved downwardly, they pull the links 94 bodily rearwardly and since these links 94 are pivotally connected to the upper rear end of the scoop, the upper rear end of the scoop is moved toward the tractor and the lower rear end is moved forwardly by the arms 35 causing rapid upward 'tilting of the scoop. As best shown in Fig. 3, the upward tilting movement of the scoop is about its heel, the heel during this stage of operation remaining continuously on the ground and being supported thereby. Thus it can be seen that the initial force required to break the material loose from its mass is carried on the ground independently of the tractor'during this initial lifting stage. Thus the tractor structure is, spared from the initial extraordinary stress load. The tilting movement of the scoop can be quite accurately compared to the manual operation of an indi vidual handling a shovel, since the forward motion of the shovel and the subsequent tilting of the same is very similar. As the shaft 31' is forced to rotate in a clockwise direction by means of the action of the cylinder and pistons 44 and 45, the depending arms also move in a clockwise direction. As the depending arms 5 move in this clockwise direction, the piston within the cylinder 54 is drawn outwardly to its extreme 'extended'position. As this piston 55 is drawn toward its extended position, fluid within the cylinder 54 is forced through the-conduit I5 and through the openings 15 and 14. Thefiuid pressure within the bored chamber 13 thereupon forces the ball valve 1201f of its valve seat II. Fluid thereupon is free to by-pass the ball valve 12 and pass through the openings 61 and 69 and thereupon through the conduit 10 into the cylinder 54. The fluid, therefore, now is in back of the piston 55 which is in its extended position and by virtue of the one waycheck action of the ball valve 12, the piston 65 is now locked. Thus thescoop 40 is locked in the tilted position which it has previously assumed. The reservoir is .filled with a sufiicient amount of hydraulic fluid so that the system is adequately supplied at all times. It also compensates for the different volumes of fluid that may be needed during different positions of the piston within the cylinder. The system is conventional in-hydraulic brake systems for vehicles and need not further be described. I i i Theoperator isnowready to raise the loaded scoop 40 from the ground. The operator there The upon rocks the control valve IOI whereby fluid is pumped to the conduit I05, which in turn causes the piston 45 to move forwardly.

The fluid which remains in front of the piston 45 is now returned by means of the conduit I04 to the pump and reservoir. As the piston 45 moves forwardly, pressure is exerted upon the crank members 41. Since the crank members 41 and the transverse'shaft 3'! are now locked against movement by the cylinder 54, continued forward movement of the piston 45 effects raising of the scoop from the ground.

As shown in Fig. 4, the piston 81 within the cylinder 83 is in its extended position during the lifting stages of the scoop and fluid pressure within the cylinder 86 keeps the piston 81 in this position. When the operator desires to release the scoop for dumping, he simply actuates the manual control lever I02, whereupon fluid within the cylinder 86 is free to return through the conduit I 06 to the reservoir and pump. The upwardly extending arms 90 thereupon rotate in a clockwise direction, thereby permitting opening of the jack-knife linkage 92 which in turn allows the scoop 40, due to gravity, to, assume the dumped position shown in Fig. 5. By manipulating the control lever I02 the operator can return the scoop 40 to its normal operating position, since fluid will reenter the cylinder 86 and cause the extension of the piston. It is of prime importance to note that by virtue of the extensible power-lift means 85, the operator can tilt the scoop 40 in a raised position to any desired angle, thereby in turn controlling the amount of material which is dumped. Thus only a portion of the material contained within the scoop may be dumped at any one time if so desired, and the amount so dumped can be accurately controlled. This feature therefore is extremely advantageous, where quantity control of dumping is necessary.

The operator is now ready to return the scoop 40 to the ground. He thereupon reverses action of the cylinder and piston arrangements 44 and 45, thereby lowering the scoop. At the same time it is .desired to return the scoop to its level position, indicated in Fig. 1, and it is therefore necessary to unlock the fluid-pressure-means or check cylinder 53. The operator thereupon rocks control valve lever I03 causing fluid to be pumped into the conduits I01 and 83, which in turn causes fluid under pressure to press against the circular portion 80 of the piston structure 18. The force against the piston structure 18' causes movement of the plunger 11 against the ball valve I2, thereby displacing thesame from the valve seat H. The 'fluid pressure which retains the piston 55 and piston rod 56 in its extended position is thereupon released and is free to flow from the cylinder 54 by means of the conduit I past the ball valve 12 and through the conduit 15' into the opposite end'of the cylinder 54. The piston 55 therefore returns to the position shown in Fig. '7, and as shown in Fig. Bthe depending arms are returned to their normal position. In this stage of operation of the valve construction 58 it is of course apparent that any excess hydraulic fluid not needed in the cylinder may be returned to the reservoir 50. From the description, it should be noted that movement of the fluid throughout the fluid pressure means 53 is occasioned entirely by the movement and operation of the cylinders 44, the fluid pressure means 53 operating primarily as a check valve construction, through which the flow may be controlled by means of the manualcontrol valve I03 nea the operator's station.

It is now readily apparent that the objects of the invention have been fully achieved. A unique construction is provided wherein the operator has full and complete control of all movements of the power loader. By virtue of the tilting arrangement of the scoop the extreme initial forces which the scoop must assume are carried on the ground independently of the tractor. During the lifting of the scoop the operator has complete control in determining what angularity the scoop should take and controlled quantity dumping is effected.

It is to be understood that modifications may be made in this construction which do not depart from the spirit of the invention as disclosed nor the scope thereof as deflned by the appended claims.

What is claimed is:

1. A loading attachment for a tractor comprising a loader frame, said frame including laterally spaced longitudinally extending frame members pivotally mounted on the tractor and extending forwardly with respect thereto, normally vertical arms connected to said frame members for swinging movement about a transverse axis, a scoop pivotally connected to said arms, a jack-knife linkage having one link pivotally connected to said scoop and a second link pivotally connected to said arms, a third link means pivotally connected to said jack-knife linkage and pivotally connected to said loader frame, and power-actuating means included on the tractor for swinging said arms whereby one end of said third link means moves said jack-knife linkage downwardly and rearwardly and said links cooperate simultaneously to tilt a portion of said shovel rearwardly and said arms move a portion of said scoope forwardly thereby raising the material engaging portion of said scoop, and whereby a portion of said scoop will be supported on the ground thereby carrying the initial lifting force on the ground independently of said tractor.

2. A loading attachment for a tractor having a longitudinal body supported on front and rear ground wheels comprising, a supporting structure on the tractor, a loader frame associated with said tractor, said loaderv frame including forwardly and downwardly extending side frame members pivotally connected to said supporting structure, laterally spaced normally upright arms pivotally connected intermediate their ends to said loader frame for oscillating movement about a transverse axis, a material carrying scoop positioned forwardly of the tractor, said scoop having a material engaging edge, means pivotally connecting the lower ends of said upright arms to said scoop about a transverse axis, said pivotal point of connection being located forwardly of the heel of said scoop when said scoop is positioned in a normal ground engaging position, a first link pivotally connected to a rear portion of said scoop, a second link pivotally connected to said first link and to the uppermost end of said upright arm, a longitudinal member pivotally connecting said links to said supporting structure, and a poweractuating means included on the tractor and connected to said upright arms for oscillating the same about a transverse axis, whereby said links and upright arms cooperate to initially raise the material engaging edge of said scoop from the ground, and whereby the heel of said scoop rotates and is supported on the ground thereby carrying the initial lifting force on the ground independently of the supporting structure and the tractor.

v 3. A loading attachment for a tractor having a longitudinal body supported on front and rear ground wheels comprising, a supporting structure on the tractor, a loader frame connected to said supporting structure, normally upright arms pivotally connected intermediate their ends to said loader frame for oscillating movement about a transverse axis, a material carrying scoop, means pivotally connecting said upright arms to said vscoop about a transverse axis, a first link pivotally connected to said scoop, a second link pivotally connected to said first link and to said upright member, means pivotally connecting said links to said supporting structure, and a poweractuating means included on the tractor and connected to said upright arms for oscillating the same about a transverse axis whereby said links and upright members cooperate to initially raise the material engaging edge of said scoop from theground, and whereby the heel of said scoop rotates and is supported on the ground thereby carrying the initial lifting force on the ground independentlyof the supporting structure'andthe tractor.

4. A loading attachment for a tractor comprising a loader frame pivotally connected to the tractor, a material moving scoop, a normally vertical arm connected intermediate its ends to said loader frame for pivotal movement about a transverse axis, means pivotally connecting said scoop to said vertical arm for tilting movement about a transverse axis, linkage means pivotally connecting said vertical arm and said scoop to said tractor, a crank arm connected to said loader frame for pivotal movement about a transverse axis, means connecting said crank arm to said vertical arm, power-actuating means included on the tractor operable in one direction to move said crank arm whereby said vertical arm and said linkage means is simultaneously actuated to tilt said scoop on the ground and thereby raise its material-engaging edge (free of the ground, and means for locking said crank arm and said scoop against pivotal movement whereby movement of said power-actuating means in a second direction will exert a force against said locked crank arm and thereby raise said loader frame and said tilted scoop free of the ground.

5. A loading attachment for a tractor comprising a loader frame pivotally connected to the tractor, a material moving scoop, a normally vertical arm connected intermediate its ends to said loader frame for pivotal movement about a transverse axis, means pivotally connecting said scoop to said vertical arm fortilting movement about atransverse axis, linkage means pivotally connecting said vertical arm and said scoop to said tractor, a crank arm connected to said loader frame for pivotal movement about a transverse axis, means connecting said crank arm to said vertical arm, power-actuating means included on the tractor and operable to move said crank arm whereby said vertical arm and said linkage means is simultaneously actuated to tilt said scoop on the ground and thereby raise its material-engaging edge free of the ground, and means for locking said crank arm and said scoop against pivotal movement whereby continued movement of said power-actuating means will exert a force against said locked crank arm and thereby raise said loader frame and said tilted scoop free of the ground.

6. A loading attachment for a tractor having a longitudinal body mounted on ground wheels, comprising a loader frame pivotally carried by the spaced side members, crank arms connected to.

said shaft forpivotal movement therewith, means connecting said crank arms to said vertical members, an extensible pressure device included on the tractor and connected to each crank arm for initially moving said crank arm to a locking position thereby tilting said scoop with a portion of said scoop being continuously supported on the ground, and a fluid pressure means connected to said transverse shaft and said loader frame for locking said crank arms in a locked position whereby subsequent movement of said extensible pressure means and said crank arm will be operable to raise said loader frame and said scoop from the ground. v

' '7. A loading attachment for a tractor having a longitudinal body mounted on ground Wheels comprising, a loader frame pivotally carried by the tractor, said loader frame including laterally spaced side members, a material moving scoop, a normally vertical arm pivotally connected intermediate its ends to each side member for pivotal movement about a transverse axis, means pivotally connecting said scoop to each vertical arm for tilting movement about a transverse axis, a transversely extending shaft pivotally carried on'said laterally spaced side members, crank arms connected to said-shaft for pivotal movement therewith, means connecting said crank arms to said vertical members, an extensible pressure device included on the tractor and connected to each crank arm for initially moving saidcrank arm in one direction into a locking position thereby tilting said scoop with a portion of said scoop being continuously supported on the ground, and a'fiuid pressure means connected to said transverse shaft and said loader frame for locking said crank arms in the locked position whereby subsequent movement ofsaid'extensible pressure means in a reverse direction will be operable to raise said loader frame and said scoop from the ground;

8. A loading attachment for a tractor having a longitudinal body supported "on front and rear ground wheels comprising, a supporting structure on the tractor, a loader frame associated with said tractor, said loader frame including side frame members connected to said supporting structure, laterally spaced normally upright arms pivotally connected intermediate their ends to said loader frame for oscillating movement about a transverse axis, a material-carrying scoop having a material-engaging edge, means pivotally connecting said upright arms to said scoop about a transverse axis, said point of connection being located near the heel of said scoop, a first link pivotally connected to a portion of said scoop, a second link pivotally connected to said first link and to one of said upright arms, a longitudinal member pivotally connecting said links to said supporting structure, and a power-actuating means included on the tractor and connected to said upright arms for oscillating the same about a transverse axis whereby said links and upright arms cooperate to initially raise the materialengaging edge of said scoop from the ground and.

7 11 whereby the heel of said scoop rotates and is supported on the ground thereby carrying the initial lifting force on the ground independently of the supporting structure and the tractor.

9. A loading attachment'fora tractor having a longitudinal body supported on front and rear ground wheels comprising, a supporting structure on the tractor, a loader frame associated with said tractor, said loader frame including side frame members pivotally connected to said supporting structure, normally upright arms pivotally connected intermediate their ends to said loader frame for oscillating movement about a transverse axis, a material-carrying scoop positioned forwardly of the tractor, said scoop having a material-engaging edge, means pivotally connecting the lower ends of said upright arms to said scoop about a transverse axis, said pivotal point of connection being located forwardly of the heel of said scoop, a first link pivotally connected to a portion of said scoop, a second link pivotally connected to said first link and to one of said upright arms, means pivotally connecting said links to said supporting structure, and a power-actuating means included on the tractor and connected to said upright arms for oscillating the same about a transverse axis whereby said links and upright arms cooperate to initially raise the material-engaging edge of said scoop from the ground and whereby the heel of said scoop rotates and is supported on the ground thereby carrying the initial lifting force on the ground independently of the supporting structure and the tractor.

10. A loading attachment for a tractor having a longitudinal body supported on front and rear ground wheels comprising, a supporting structure on the tractor, a loader frame associated with said tractor, said loader frame including forwardly and downwardly extending side frame members pivotally connected to said supporting structure, laterally spaced normally upright arms pivotally connected intermediate their ends to said loader frame for oscillating movement about a. transverse axis, a material-carrying scoop positioned forwardly of the tractor, said scoop having a material-engaging edge, means pivotally connecting the lower ends of said upright arms to said scoop about a transverse axis, said pivotal point of connection being located forwardly of the heel of said scoop, a first link pivotally connected to a rear portion of saidscoop, a second link pivotally connected to said first link and to the uppermost end of one of said upright arms, a longitudinal member pivotally connecting said links to said supporting structure, and a poweraotuating means included on the tractor and connected-to said upright'arms for'oscillating thesame about a transverse axis whereby-said links and upright arms cooperate to initially raise the material-engaging edge of said scoop from the ground and whereby the heel of said scoop rotates and is supportedon the groundthereby carrying the initial lifting force on-the ground independently of the supporting structure -and the tractor.

11. A loading attachment for atractorcom prising a loader frame said frame including laterally spaced, longitudinally extending; side members pivotally connected to the tractor and extending forwardly with respect thereto, a material moving scoop, for'pivotal tilting movement about a transverse axis, an extensible power means supported by the tractor,-a norrnally-ver tically extending arm pivotally connected to the side members, means pivotally connecting the lower portion of said vertical arm to a lower rearward portion of said scoop, linkage means pivotally connnected to an upper rearward portion of said scoop, means pivotally connecting the linkage means to the loader frame, means pivotally connecting the extensible power means to the upper-portion of said arm, saidextensible power means being adapted to move in one -di rection thereby pivoting said arm to tilt the 'toe of said scoop from the ground whereby the 'heel of said scoop is supported on the ground, and a fluid pressure extensible device supported on the loader frame and connected to the scoop, said fluidpressure extensible device-being adapted to lock said scoop in its tilted position, the exten- 'sible power means being movable in a second direction thereby raising said frame and said scoop.

GORDON G. 'McNAMARA, JR.

REFERENCES CITED The following references are of .recordin the file of this patent:

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